This paper describes the first report of dioxins and furans (PCDDs/Fs) in sediment cores from Mexico. Sedimentation rates and vertical fluxes were estimated using ²¹⁰Pb dating. Two cores correspond to marine sediments and one to an endorheic lake. Concentrations of PCDDs/Fs found in the three sites are typical of non-impacted areas with low concentrations when compared to reference values. However the PCDDs/Fs sediment profiles show an increasing concentration trend in the upper core sections. This behavior is different from that found at many sites around the globe where diminishing concentrations have been reported. A strong predominance of OCDD was observed, and a comparison to typical composition profiles of industrial and other sources did not result in clear origin assignments for these measured compounds. We suggest that local sources may be responsible for the increase in concentration and, because these undetermined sources have not been curtailed, their importance is still growing.

PCBs (as Aroclor concentrations) have been extensively examined in fish along the Hudson River, but other xenobiotic chemicals in fish have had limited assessment. This study determined concentrations and congener distributions of polybrominated diphenyl ethers (PBDEs), polybrominated and polychlorinated dibenzo-p-dioxins and dibenzofurans (PBDD/Fs and PCDD/Fs), and polychlorinated biphenyls (PCBs) in smallmouth bass and striped bass taken from a 385km reach of the Hudson River. Concentrations of PBDEs and PCBs in smallmouth bass, and PCBs in striped bass, were positively related to human uses of the compounds in the basin. Generally low levels of PCDD/Fs were found. One striped bass, however, contained elevated 2,3,7,8-TCDD, indicating exposure to a known source in the adjacent Newark Bay-Passaic River basin. PBDDs were generally below detection. PBDFs were present in four of 18 smallmouth bass, but were not detected in striped bass. Dioxin-like PCBs contribute most to 2,3,7,8-TCDD toxic equivalents in 29 of 30 samples.

Organic pollutants such as polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs), polychlorinated biphenyls (PCBs), polychlorinated naphthalenes (PCNs) and polycyclic aromatic hydrocarbons (PAHs), as well as some metals are periodically monitored in soil and vegetation samples collected in Tarragona County (Spain). We here report the temporal trends of the concentrations of the above pollutants between the initial survey (2002) and that recently (2009) performed. The area under evaluation was divided into 4 sections (chemical, petrochemical, urban/residential and unpolluted). In general terms, urban soils presented the highest concentrations of PCDD/Fs, PCNs and PAHs, confirming that traffic is a very important emission source of these pollutants. In addition, substantially higher levels of PAHs and some metals were found in vegetation samples from the petrochemical complex. The assessment of health risks of these contaminants indicated that the current concentrations of micropollutants did not mean additional non-carcinogenic or cancer risks for the population living in the zone.

The concentrations, compositional profiles, and potential ecological risk of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs), polychlorinated biphenyls (PCBs) and polychlorinated naphthalenes (PCNs) in sediments of the Daliao River Estuary were investigated. Total concentrations of PCDD/Fs, PCBs, and PCNs were in the range of 11.3–133.2ng/kg dry weight (dw), 1 971–37 632ng/kg dw and 33.1–284.4ng/kg dw, respectively. The total TEQ values varied from 0.37 to 4.08ng/kg dw, with the dominant contributions by PCDD/Fs, then by PCBs and PCNs. The spatial distributions of PCDD/Fs, PCBs and PCNs in the river estuary were much related to hydrodynamic conditions. The risk of contamination to the deeper sea was increased in the flood seasons. Moreover, our data confirmed that both organic matter in sediments and molecular properties of dioxin-like compounds were the factors which strongly influenced the partition behavior of these dioxin-like compounds between sediments and water phase in the estuarine zone.

Six sediment samples collected from the Gulf of Mexico were analyzed. Total concentrations of the PAHs ranged from 52 to 403ngg⁻¹ dry weight. The lowest PAH concentration without 5–6 rings PAHs appeared in S-1 sample associated with gas hydrate or gas venting. Moreover, S-1 sample had the lowest organic carbon content with 0.85% and highest reduced sulfur level with 1.21% relative to other samples. And, analysis of the sources of PAHs in S-1 sample indicated that both pyrogenic and petrogenic sources, converserly, while S-8, S-10 and S-11 sample suggested petrogenic origin. The distribution of dibenzothiophene, fluorine and dibenzofuran and the maturity parameters of triaromatic steranes suggested that organic matters in S-1 sample were different from that in S-8, S-10 and S-11 sample. This study suggested that organic geochemical data could help in distinguish the characteristic of sediment associated with gas hydrate or with oil seepage.

Background, aim, and scope Biowaste contains compounds of agricultural value such as organic carbon, nutrients, and trace elements and can partially replace mineral fertilizer (MIN) and improve the physical properties of the soil. However, the obvious benefits of land spreading need to be carefully evaluated against potential adverse effects on the environment and human health. Environmental contamination resulting from biowaste application is one of the key variables when assessing cost/benefits. This study provides data on the resulting concentration of polychlorinated dibenzodioxins and dibenzofurans (PCDD/Fs) and dioxin-like polychlorinated biphenyls (DL-PCBs) in the soil column as a result of the different types of fertilizers. Materials and methods In a long-term field experiment established in 1962, we investigated the influence of the application of biowaste-derived fertilizers such as sewage sludge (SSL), compost (COM), and farmyard manure (FYM) to a luvisol derived from loess on the contents of PCDD/Fs and DL-PCBs. Control plots amended only with MIN served as a basis to compare the biowaste-amended soils with soils affected only by atmospheric deposition, thus experimentally separating the two pathways of soil contamination. Samples of the soil column down to a depth of 90 cm were taken in 2001 and analyzed for PCDD/Fs and dioxin-like PCBs according to US-EPA methods 1613 and 1668, respectively. Results Thirty-nine years of experimental SSL and COM applications exceeding four times the maximal amount as laid down in German legislation resulted in a doubling of the international toxicity equivalent (I-TEQ) budget for PCDD/Fs and a threefold increase for DL-PCBs as compared to test plots amended with MIN only. As compared to MIN, the application of FYM had no effect on the PCDD/F and PCB content in soil. The average contribution of the DL-PCBs to the WHO-TEQ was 19% in the MIN and FYM plots and somewhat higher in the COM (23%) and in the SSL (27%) plots. Discussion Although the test plots received four times the maximum application of SSL as laid down in the German SSL ordinance and the investigated region represents the upper end of the topsoil concentrations typically found in Germany, the soils treated with SSL and COM were still a factor of 4 below the German guideline value of PCDD/Fs for arable land. No enhancement of translocation of PCDD/Fs and PCBs into the corresponding subsoils due to the presence of dissolved humic matter or other surfactants potentially present in the biowaste was observed. The similarity of congener patterns in all soils, irrespective of the type of fertilizer applied, points towards atmospheric deposition of PCDD/Fs and DL-PCBs as the main intake route in the soils. The higher levels in the SSL- and COM-amended soils can be explained by the fact that both biowastes are subject to atmospheric deposition occurring at their origin. In the case of COM, it is accumulation in the foliage, while in the case of SSL, atmospheric particulate from wet and dry deposition is collected in the wastewater treatment system via urban runoff. Conclusions It appears that the common practice of SSL applications in Germany does not pose a current threat to the agro-environment with regard to PCDD/Fs and DL-PCBs. However, time trend data on PCDD/Fs in SSL-amended soils will be needed to obtain a prognosis about the long-term effect of biowaste applications on soil quality.

BACKGROUND, AIM, AND SCOPE: Topographical and meteorological factors, such as monsoons, can drastically affect ambient dioxin levels. In order to better understand these phenomena, four sampling lines (comprising 16 sampling sites) were selected in accordance with the topographical characteristics and the transport paths of the Taichung Basin. MATERIALS AND METHODS: The ambient air samples were simultaneously collected according to US EPA TO-9A. Seventeen polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) were analyzed by a high-resolution gas chromatograph/high-resolution mass spectrometer. RESULTS: Field measurements indicated that, during monsoons, PCDD/Fs concentrations varied from 128 to 4,230 fg m−3. Two locations, the pass between two tablelands and the valley in front of a mountain, had the highest PCDD/Fs concentrations; those concentrations were about two to five times greater than the average concentration. There were 189 analyses of 11 kinds of PCDD/Fs emission sources used to develop emission fingerprints for a CMB8.2 simulation. Chemical mass balance (CMB8.2) model simulation with PCDD/Fs and surface wind field measurements were performed. Results of CMB8.2 modeling indicated that the major source of most sites was secondary copper smelting. CONCLUSIONS: The CMB8.2 model indicated the effects of hills and river valleys on pollutant transport. Results indicated that secondary copper smelting must be controlled to reduce the ambient concentrations of PCDD/Fs in the Taichung Basin.

PURPOSE: Heterocyclic aromatic compounds containing nitrogen, sulfur, or oxygen heteroatoms (NSO-HET) have been detected in air, soil, marine, and freshwater systems. However, only few publications are available investigating NSO-HET using in vitro bioassays. To support better characterization of environmental samples, selected NSO-HET were screened for dioxin-like activity in two bioassays. METHODS: The present study focuses on the identification and quantification of dioxin-like effects of 12 NSO-HET using the DR-CALUX assay, and the 7-ethoxyresorufin-O-deethylase (EROD) assay with the permanent fish liver cell line RTL-W1. Changes of the total medium compound concentrations during the test procedure due to, e.g., sorption or volatilization were quantified using GC/MS. RESULTS: The NSO-HET benzofuran, 2,3-dimethylbenzofuran, dibenzofuran, dibenzothiophen, acridine, xanthene, and carbazole caused a response in the DR-CALUX assay. Only benzofuran and 2,3-dimethylbenzofuran were also positive in the EROD assay. All other compounds were inactive in the EROD assay. Relative potency (REP) values ranged from (2.80 ± 1.32) · 10−8 to (3.26 ± 2.03) · 10−6 in the DR-CALUX and from (3.26 ± 0.91) · 10−7 to (4.87 ± 1.97) · 10−7 in the EROD assay. CONCLUSIONS: The REP values were comparable to those of larger polycyclic aromatic hydrocarbons, e.g., fluoranthene and pyrene. Thus, and because of the ubiquitous distribution of heterocyclic aromatic compounds in the environment, the provided data will further facilitate the bioanalytical and analytical characterization of environmental samples towards these toxicants.